1. Field of the Invention
The present invention relates to a gas turbine driven power plant, and more specifically to one that burns a dirty fuel like coal.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
A gas turbine engine is a very efficient converter of fuel to energy, and is typically powered by natural gas or a liquid fuel. Coal burning power plants burn coal, the coal being a very cheap source of energy but also contains residue from the combustion process that would damage a turbine if used in the gas turbine power plant. Gas turbine power plants in the past have used heat from burning coal to heat the gas supplied to the turbine, but through a heat exchanger such that the residue from burning coal does not enter the turbine. This heat exchanger is not very efficient in transferring heat, and the maximum operating temperature is limited to what the heat exchanger materials can withstand. The efficiency of a gas turbine increases as the temperature of the hot gas stream increases. Coal can burn to produce a very hot gas stream. However, modern day materials used to make heat exchangers cannot withstand this high temperature. Oil based fuels are burned for use in driving gas turbines, but the cost of oil based fuels have increased in recent years. Coal is a very abundant and relatively cheap fuel.
It is therefore an object of the present invention to provide for a power plant that makes use of the very high energy conversion of a gas turbine with the relatively cheap and abundant use of coal as the heat producing fuel.
It is another object of the present invention to make use of a dirty fuel like coal that can burn at a very high temperature, and use the heated gas in a gas turbine for producing power.